[levabalkin]

Will the above infrastructure be able to handle my requirements? Can it be improved?

Not necessarily an improvement, but a different perspective on the computing section. I assume you run the services in containers. Instead of handling EC2 instances, you can run the workloads in ECS Services with the Fargate Spot capacity provider and autoscale based on the number of requests per target group or cpu load or time intervals. Github Actions can continuously deploy such services after you terraformed the infrastructure.